<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        canvas{
            border:1px solid blue;
            margin:30px auto;
        }
    </style>
</head>
<body>
    <canvas width="800" height="600"></canvas>
    <script>
        // 刮刮卡、画画，我们可以用canvas来实现
        // 复杂
        // html5提供的api，可以实现画画 操作图片 像echarts底层都是用的canvas
        // 刮刮卡 
        var canvas = document.querySelector('canvas');
        var huabi = canvas.getContext('2d');
        huabi.fillStyle = 'blue'
        huabi.fillRect(20,20,40,30)
    </script>
</body>
</html>